The invention relates to a lock for car doors, particularly for trunk lids.
The locks known in the art having a locking cylinder which is released relative to the lock itself by a key and, in turn, releases or arrests the arresting device of the lock relative to the chassis of the car. In order to effect the release, the locking cylinder is generally either rotated with the help of the key or is itself pushed into the lock. In the first case, the locking cylinder terminates flush with the chassis and, in the second case, the locking cylinder projects out of the chassis by a certain distance or is pushed into the chassis to the required depth.
In both cases, the locking cylinder, or the individual components which are casually or functionally connected therewith, move inside the lock from the outer surface of the chassis to the interior of the chassis and, after actuation of the arresting device, are returned to their original positions by suitable means, e.g., spring force. For cylinders which must be depressed and are not flush with the chassis in the original position, such original position, as a rule, is one in which the projecting length is that required to actuate the arresting or releasing mechanism relative to the chassis, i.e., approximately 8-15 mm beyond the outer surface of the chassis.
In a very large number of instances, the locking cylinder is, however, in the absence of another possibility, also used as a handle to close the trunk lid, particularly when this is dirty. For a lock structure with a projecting locking cylinder, the projecting part of the latter is used as a handle; for locks which require a rotation of the key or are pushed in from a flush outer surface to effect release, the inserted key is readily employed as a handle. All possible modes of use--which cannot be enumerated here because of their large number and are represented by the preceding examples--have the purpose of allowing the user to close the trunk lid without soiling himself in the event that the outer surface is dirty.
Conventional locks with their present design cannot, or can only partially, accomplish this purpose. For locks having rotating cylinders or a flush design, the user does have available a clean aid--which does not soil his hands--in the form of his key. However, the mechanical strength of a key is not selected with a view to such uses and breakage of the key with the accompanying inconvenience is very often the result. Locks with projecting locking cylinders are not available free of dirt since the projecting part is exposed to road dirt and the desired result is not achieved. While the dirty surface to be gripped is smaller than if one had to touch the trunk lid itself in order to close the same, it would nevertheless be desirable that no dirty parts need be touched.